CRL Thru-Glass Two-Way Digital Electronic Communicators contain the latestadvancements in electronic sound transmission devices. Clear, distortion free two-wayconversations can take place through secure barriers as the unit senses volume levelsand automatically activates when speech begins. Easy to operate multi-function controlscan easily be set by the clerk to turn the Communicator on and off, set to mute, use the'wake-up' mode, and to adjust volume.An industry first, the CRL Thru-Glass Two-Way Digital Electronic Communicator canbe used by the clerk with an optional Gooseneck Microphone with USB plugs, one of thethree Headsets shown on page G458, or when ideal conditions exist, simply by speakinginto the Communicator's built-in microphone.Select either the 120V AC Plug-In Transformer model, or the 12V DC RechargeableBattery Powered model. Units are available as standard or bullet resistant models insatin or black anodized finishes. CRL Digital Communicators are easy to install. Theabsence of exterior screws or fasteners make them tamper-resistant. All units aresupplied complete with mounting hardware and instructions to fit 1/4" to 1/2" (6 to 12mm) thick barrier glass, and up to a 4" (102 mm) barrier when using the suppliedextension screws and mounting brackets.